Chemical signatures of the first star clusters

Details Chemical signatures of the first star clusters Chemical signatures of the first star clusters

2010-07-30

arxiv.org/abs/1007.5374v1

Astronomy and Astrophysics

Astrophysics

Cosmology and Extragalactic Astrophysics

24 pages, 17 figs; Astrophysical Journal (Sept 20 issue); a full copy is available at http://sydney.edu.au/science/physics/~

Scientific paper

The chemical abundance patterns of the oldest stars in the Galaxy are expected to contain residual signatures of the first stars in the early universe. Numerous studies attempt to explain the intrinsic abundance scatter observed in some metal-poor populations in terms of chemical inhomogeneities dispersed throughout the early Galactic medium due to discrete enrichment events. Just how the complex data and models are to be interpreted with respect to "progenitor yields" remains an open question. Here we show that stochastic chemical evolution models to date have overlooked a crucial fact. Essentially all stars today are born in highly homogeneous star clusters and it is likely that this was also true at early times. When this ingredient is included, the overall scatter in the abundance plane [Fe/H] vs. [X/Fe] (C-space), where X is a nucleosynthetic element, can be much less than derived from earlier models. Moreover, for moderately flat cluster mass functions (gamma < 2), and/or for mass functions with a high mass cut-off (M_max > 10^5 M_sun), stars exhibit a high degree of clumping in C-space that can be identified even in relatively small data samples. Since stellar abundances can be modified by mass transfer in close binaries, clustered signatures are essential for deriving the yields of the first supernovae. We present a statistical test to determine whether a given set of observations exhibit such behaviour. Our initial work focusses on two dimensions in C-space, but we show that the clustering signal can be greatly enhanced by additional abundance axes. The proposed experiment will be challenging on existing 8-10m telescopes, but relatively straightforward for a multi-object echelle spectrograph mounted on a 25-40m telescope.

Affiliated with

Also associated with

No associations

Rating

Chemical signatures of the first star clusters does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Chemical signatures of the first star clusters, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Chemical signatures of the first star clusters will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-700073